The invention, on the one hand, relates to a method of producing an electrically conductive connection between a contact element, which interacts with a corresponding counter-contact element, and several electric lines, each consisting of several stranded wires, and, on the other hand, to a contact element produced in such a manner.
Such contact elements are produced particularly for mechanically highly stressed applications, as in the case of a motor vehicle, as a rule, by means of a crimping process. In this case, crimping elements molded onto the contact element are pressed together at a high pressure until they are connected with the contact element in a contact-making manner. Particularly when designed for a long-time operation, this process creates some uncertainty. When used, for example, for a grounding connection, this uncertainty is noticeable as transient, not always reproducible interruptions of the grounding connection. It may also occur that an electric line is absent or is pulled at the free end out of the contact area, for example, by a subsequent stripping operation.
It is an object of the invention to provide a method by which a contact element of the above-mentioned type is completely produced in a reliable and durable manner. In an advantageous application of the method, the contact element should be mechanically additionally particularly loadable and/or usable as a ground cable socket.
The solution of this task is achieved by a method of producing an electrically conductive connection between a contact element, which interacts with a corresponding counter-contact element, and several electric lines, each consisting of several stranded wires. The lines are deposited on a plane supporting surface of the contact element. The completeness of the lines is checked, and subsequently, the lines are fixed by use of a resistance welding operation in a contact-making manner on the contact element. Contact elements which have the indicated special characteristics are provided, wherein the supporting surface additionally has two crimping elements which surround the lines. The contact element may be constructed as a ground cable socket which is held on a ground bolt by way of a screwed connection.
A flat supporting surface in the sense of the invention means that it is planar or a contour rounded in its cross-section whose radius is significantly larger than the radius of the attached lines. By means of the targeted shaping of the cross-section, the process reliability of the welding operation can clearly be increased, because, before, during and after the welding operation, the cross-section corresponds to defined data and the entire process thereby becomes precisely controllable. The examination of the completeness of the lines before the actual welding operation ensures that the welding operation will be carried out only if all provided lines are present. Finally, the resistance welding operation provides a long-term-stable and electrically well-conducting connection of the lines with the contact element.
Advantageous further developments of the invention are described and claimed herein.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.